Great lumbering giant that it is, the European institutions have the potential to drag reluctant western governments into agreements to tackle climate change. The Green group in particular has done some good work on this.
However, it doesn't always go well.
The European Council and Parliament have reached agreement on new rules to limit CO2 emissions from cars...or rather reached agreement to postpone them. The result would mean the cars on the market in 4 years will be no more fuel efficient (or less climate-damaging) than they are now, while deeper long term improvements are also jeopardised.
More at http://www.stopclimatechange.net/